Apparatus for casting steel.



E. F. LAW & C. P. SANDBERG.

APPARATUS FOR CASTING STEEL.

APPLICATION FILED APR. 17. I916- .d R j g ZCZwardZf @111 MraLSZiaraP, azde g p l p EDWARD FULTON LAW, OF MANCHESTER, AND CHRISTER PETERSANDBERG, OF WEST- MINSTEIIBJ, LONDON, ENGLAND, ASSIGNORS F ONE-THIRD T0SIR W. G. ARMSTRONG,"

WHITWOETH AND COMPANY, LIMITED, OF NEWCASTLE-UPON-TYNE, ENGLAND.

APPARATUS FOR CASTING STEEL.

momma.

Specification of Letters Patent.

Patented Dec. 5,1W1IU8.

Application filed April 17, 1916. Serial No. 91,685.

'LAW and CHRIsTnR PETER SANDBERG, sub

jects of the King of Great Britain, residing, respectively, at Sir W. G.Armstrong, Whitworth &' Co.s Works, Ashton Eoad, 0penshaw, Manchester,England, and 9 Bridge street, Westminster, London, England, haveinvented new and useful Improvements 1n Apparatus for Casting Steel, ofwhich the following is a specification.

It is well known that in the production of large steel ingots what istermed plping generally occurs at the top of the ingot. This arises fromthe fact that the ingot cools and solidifies mainly inwardly andupwardly from the outside and the bottom, while a surface cooling andhardening takes place at the top, contraction of the metal, as

it cools, taking place at the same time. Blow holes and so-calledsegregation also frequently occur in the upper portion of the ingotowing to the same causes. These defects in the upper part of the ingotalways necessitate the removal of the end portion of the ingot sometimesas much as one-third or even more of the ingot having to be cut off, theportion cut off being known as a crop end or dead head.

Similar difficulties occur in the production of other steel castings,particularly such as are of large size.

Hereinafter we use the word casting as including an ingot.

According to this invention we employ for the production of steelcastings according to the method disclosed and claimed in our copendingapplication, Serial No. 91,684, a mold which has at its bottom above thebase a loose contact device such as a metal plate,

. connected to a source of electricity, and an electrode above the moldwhich is also connected to the source of electricity so that an arc canbe struck between the top of the casting and this electrode.

The drawing shows by way of example and more or less diagrammatically avertical section of casting apparatus constructed in accordance withthis invention.

At the bottom of the mold A and resting on the base 18 is provided ametal plate C having a tongue C to which is connected one of the leads Dfrom a convenient source E of electricity. The plate C may be made ofsteel, iron or other suitable metal. The

.other lead F from the source of electricity is connected to anelectrode G. A cover H may prevent the escape of heat when the arc is inoperation.

, When an ingot is to be cast, the contact plate C is placed on the baseB, the mold A is placed in position and the metal is poured into themold. As soon as possible after the mold is filled, the cover H and theelectrode G are lowered into position over thetop of the mold and thecurrent is switched on. The current passes on the one hand through thelead D', plate C and the metal of the ingot, which by partial welding ismaintained in good contact with the plate, and on the other hand by thelead F and the adjustable electrode G, and an arc is formed between themolten metal at the top of the mold and the electrode. The heat producedthereby maintains the metal at the top of the ingot fluid until the restof the ingot has solidified and so prevents the formation of pipes orblow holes and segregation. When the ingot has cooled, the tongue C isknocked off as is also the plate C if the latter has not adhered toofirmly to the ingot, otherwise it is removed with the crop end which isalways out OK from the bottom of the ingot. What we claim is 1. Inapparatus for casting steel, the combination of a mold, a source ofelectricity, a loose contact device situated close above the mold baseand connected to one pole of the source of electricity and an electrodeabove the mold connected to the other pole thereof.

2. In apparatus for casting steel, the

.' pole of the source of electricity; an electrode above the moldconnected to the other pole thereof and a cover adapted to be placedover the top of the mold.

3. In apparatus for casting steel, the com bination of a mold, a sourceof electricity, a loose metal plate situated close above the mold baseand connected to one pole of the source of electricity, an electrodeabove the mold connected to the other pole thereof and a acover adaptedto be placed over the top

